It is indeed an OBE and don't worry, you don't leave an empty body behind, you simply expand your energy and move your conscious awareness. If you go too far, you'll either wake up completely (that is, snap out of your trance state, which you're in) or go into an astral lansdscape, which will be like shifting into a dreamscape. No worries, it's all good.
For more info, check out this: http://www.astraldynamics.com.au/con...ral-projection